from __future__ import annotations

import json
from pathlib import Path

import pytest

import worker


class FakePipeline:
    def __init__(self, model_path: str, device: str, config: dict[str, object], busy_path: Path, output: str = "Synthetic title"):
        self.model_path = model_path
        self.device = device
        self.config = config
        self.busy_path = busy_path
        self.output = output
        self.calls: list[tuple[str, int]] = []

    def generate(self, prompt: str, *, max_new_tokens: int):
        self.calls.append((prompt, max_new_tokens))
        before = int(self.busy_path.read_text().strip())
        self.busy_path.write_text(str(before + 1234))
        return self.output


class FakeGenAI:
    def __init__(self, busy_path: Path, output: str = "Synthetic title"):
        self.busy_path = busy_path
        self.output = output
        self.pipeline: FakePipeline | None = None

    def LLMPipeline(self, model_path: str, device: str, *args: object, **kwargs: object):  # noqa: N802 - mirrors OpenVINO API
        if args and isinstance(args[0], dict):
            config: dict[str, object] = {str(k): v for k, v in args[0].items()}
        else:
            config = dict(kwargs)
        self.pipeline = FakePipeline(model_path, device, config, self.busy_path, self.output)
        return self.pipeline


@pytest.fixture()
def worker_paths(tmp_path: Path):
    model_path = tmp_path / "model"
    cache_dir = tmp_path / "cache"
    busy_path = tmp_path / "npu_busy_time_us"
    model_path.mkdir()
    busy_path.write_text("100")
    return model_path, cache_dir, busy_path


def test_generate_uses_npu_config_and_reports_busy_delta(monkeypatch: pytest.MonkeyPatch, worker_paths):
    model_path, cache_dir, busy_path = worker_paths
    fake_genai = FakeGenAI(busy_path)
    monkeypatch.setattr(worker, "import_openvino_genai", lambda: fake_genai)

    npu_worker = worker.NpuWorker(str(model_path), str(cache_dir), busy_path=busy_path, bind_port=18820)
    result = npu_worker.generate("title", "Synthetic non-private kanban notification.", max_new_tokens=24)

    assert result.npu_busy_before_us == 100
    assert result.npu_busy_after_us == 1334
    assert result.npu_busy_delta_us == 1234
    assert result.text == "Synthetic title"
    assert fake_genai.pipeline is not None
    assert fake_genai.pipeline.device == "NPU"
    assert fake_genai.pipeline.config["CACHE_DIR"] == str(cache_dir)
    assert fake_genai.pipeline.config["MAX_PROMPT_LEN"] == 1024
    assert fake_genai.pipeline.calls[0][1] == 24


def test_memory_alias_json_wrapping(monkeypatch: pytest.MonkeyPatch, worker_paths):
    model_path, cache_dir, busy_path = worker_paths
    fake_genai = FakeGenAI(busy_path, output='[{"fact":"synthetic stable preference","confidence":0.8}]')
    monkeypatch.setattr(worker, "import_openvino_genai", lambda: fake_genai)

    npu_worker = worker.NpuWorker(str(model_path), str(cache_dir), busy_path=busy_path)
    result = npu_worker.generate("memory_candidate", "Synthetic user says they prefer concise answers.")

    assert result.parsed_json is not None
    assert result.parsed_json["candidates"][0]["fact"] == "synthetic stable preference"
    assert "wrapped" in result.parsed_json["notes"]


@pytest.mark.parametrize(
    ("job", "user_input", "max_new_tokens", "message"),
    [
        ("bad", "hello", 1, "unsupported job"),
        ("title", "", 1, "non-empty"),
        ("title", "x" * (worker.MAX_INPUT_CHARS + 1), 1, "input too long"),
        ("title", "hello", worker.MAX_NEW_TOKENS + 1, "max_new_tokens"),
    ],
)
def test_validation_errors(monkeypatch: pytest.MonkeyPatch, worker_paths, job: str, user_input: str, max_new_tokens: int, message: str):
    model_path, cache_dir, busy_path = worker_paths
    monkeypatch.setattr(worker, "import_openvino_genai", lambda: FakeGenAI(busy_path))
    npu_worker = worker.NpuWorker(str(model_path), str(cache_dir), busy_path=busy_path)

    with pytest.raises(ValueError, match=message):
        npu_worker.generate(job, user_input, max_new_tokens=max_new_tokens)


def test_health_reports_actual_bind_and_limits(worker_paths):
    model_path, cache_dir, busy_path = worker_paths
    npu_worker = worker.NpuWorker(str(model_path), str(cache_dir), busy_path=busy_path, bind_host="127.0.0.1", bind_port=18821)

    health = npu_worker.health()

    assert health["bind"] == "127.0.0.1:18821"
    assert health["max_input_chars"] == 6000
    assert health["max_new_tokens"] == 256
    assert health["busy_time_us"] == 100


def test_response_payload_shape(worker_paths):
    model_path, cache_dir, busy_path = worker_paths
    npu_worker = worker.NpuWorker(str(model_path), str(cache_dir), busy_path=busy_path)
    result = worker.GenerationResult(
        text="ok",
        parsed_json={"severity": "info"},
        timing_ms={"load": 1.0, "initial_load": 1.0, "generate": 2.0, "total": 3.0},
        npu_busy_delta_us=5,
        npu_busy_before_us=10,
        npu_busy_after_us=15,
    )

    payload = worker.response_payload(npu_worker, "notification", result)

    assert json.dumps(payload)
    assert payload["device"] == "NPU"
    assert payload["job"] == "notification"
    assert payload["json"] == {"severity": "info"}